Background: A retrospective study of long term outcome after the development of metastases from osteosarcoma was performed, with emphasis on the impact of different treatment strategies and the identification of prognostic factors.
Methods: From 1975 to 1993, a population-based series of 60 patients with distant metastases (relapse) from high grade, extremity-localized osteosarcoma was treated at The Norwegian Radium Hospital. Six patients relapsed after surgery alone, 28 patients relapsed after primary chemotherapy of low potency, and 26 patients after modern, intensive chemotherapy. Lung metastases were present in 88% of the patients, 52% had bilateral lesions, and the median number of lesions was three (range, 1-25 lesions). Forty-seven percent of patients had complete surgical excision of all identifiable metastatic nodules and 54% of these had additional second line chemotherapy defined as adequate. Adequate chemotherapy included further dose escalations of methotrexate in approximately half of the patients, usually from 8 to 12 g. The rest were exposed to novel agents such as cisplatin, etoposide, and ifosfamide. Of the operated patients, 43% had additional thoracotomies after subsequent relapses.
Results: The projected 5-year survival rate from the first metastatic event was 24% for all patients and 50% for patients who underwent complete metastasectomy. In a multivariate analysis, the factors with independent predictive value for improved overall survival were the presence of a solitary metastasis, the accomplishment of complete metastasectomy, and the administration of adequate salvage chemotherapy.
Conclusions: Complete metastasectomy is mandatory for long term survival of patients with metastatic osteosarcoma, and repeated lung resections are necessary in nearly half the patients. Second line chemotherapy and following primary treatment with modern intensive chemotherapy protocols may improve survival further.